I've been using i3 for some time and IMHO it's one of the most feature complete (e.g. dynamic/re-nameable workspaces/tags) , thought through, reliable, established and easily configurable tilings WMs out there.
However, it's too manual (although it provides limitless flexibility) for me and I'd like my WM to be more dynamic and automatic, like dwm (which is too static for me in terms of tag creation/renaming and has separate tagsets for workspace) or XMonad (bug 426772 rules it out for the moment and Haskell configuration is somewhat cumbersome) . And being able to set multiple tags/workspaces on windows would also be nice.

So could anyone recommend such a WM that would be as polished as i3 but would be dynamic?

I used Awesome before i3, but what really pissed me off is that when you change the XRandR screen configuration, it restarts and looses information about client position on dynamically created workspaces (I used the shifty library for that). Otherwise it was almost perfect.

I've already looked into qtile, it's still in early stages of development and lacks many features I'd like.

catwm is abandoned and essentially just an improved dwm

Right now it looks like I'll have to decide between dwm, awesome and xmonad. Dwm is too static, awesome restarts on monitor change, so XMonad seems to be the only viable choice for me for the moment (that wakeup bug has a workaround).